Contributors to and impact of residual shunting after device closure of atrial septal defects.

BACKGROUND: The prevalence of residual shunt in patients after device closure of atrial septal defect and its impact on long-term outcome has not been previously defined. METHODS: From a prospective, single-institution registry of 408 patients, we selected individuals with agitated saline studies performed 1 year after closure. Baseline echocardiographic, invasive hemodynamic, and comorbidity data were compared to identify contributors to residual shunt. Survival was determined by review of the medical records and the Social Security Death Index. Survival analysis according to shunt included construction of Kaplan-Meier curves and Cox proportional hazards modeling. RESULTS: Among 213 analyzed patients, 27% were men and age at repair was 47 ± 17 years. Thirty patients (14%) had residual shunt at 1 year. Residual shunt was more common with Helex (22%) and CardioSEAL/STARFlex (40%) occluder devices than Amplatzer devices (9%; P = .005). Residual shunts were more common in whites (79% vs 46%, P = .004). At 7.3 ± 3.3 years of follow-up, 13 (6%) of patients had died, including 8 (5%) with Amplatzer, 5 (25%) with CardioSEAL/STARFlex, and 0 with Helex devices. Patients with residual shunting had a higher hazard of death (20% vs 4%, P = .001; hazard ratio 4.95 [1.59-14.90]). In an exploratory multivariable analysis, residual shunting, age, hypertension, coronary artery disease, and diastolic dysfunction were associated with death. CONCLUSIONS: Residual shunt after atrial septal defect device closure is common and adversely impacts long-term survival.

Incremenal Value of Cardiac Magnetic Resonance for Assessing Pulmonic Valve Regurgitation.

BACKGROUND AND AIM OF THE STUDY: Cardiac magnetic resonance (CMR) is the 'gold standard' for quantifying pulmonic regurgitation (PR) in adults with congenital heart disease, but remains costly and is less readily available than echocardiography. Qualitative echocardiographic assessment of PR is challenging, and guiding criteria are limited. It is unknown if echocardiography is sufficient to screen for significant PR. The study aim was to determine whether cardiac MRI provides additional benefit in the assessment of PR in adults with congenital heart disease. METHODS: Patients with repaired tetralogy of Fallot or congenital pulmonic stenosis after valvotomy undergoing transthoracic echocardiography and CMR with no interval intervention were identified from a prospective registry. Patients with greater than mild pulmonic stenosis, residual ventricular septal defect or poor echocardiographic windows were excluded. Whole-cohort and subgroup (tetralogy of Fallot versus pulmonic stenosis) analyses for inter-modality agreement were performed. RESULTS: A total of 48 patients (24 men, 24 women; mean age 43 +/- 12 years) was included in the analysis. The unweighted kappa value for the two modalities was 0.30, suggesting 'fair' agreement, though only 52% had matching PR assessments. The indexed right ventricular end-systolic volume (RVESVi) correlated closely with cardiac MRI-monitored PR (p = 0.011 by analysis of variance), but not with that monitored with echocardiography (p = 0.081). Subgroup analysis demonstrated less inter-modality agreement in the tetralogy of Fallot population (kappa 0.25) than in the pulmonic stenosis population (kappa 0.35). CONCLUSION: CMR measurement of PR correlates closely with the RVESVi, and appears superior to echocardiography when assessing patients at risk for PR. The study results suggest a vital role for CMR whenever significant PR is suspected in the adult congenital heart disease population.

Quantitative and qualitative perceptions of the 2011 residency duty hour restrictions: a multicenter, multispecialty cross-sectional study.

BACKGROUND: July 2011 saw the implementation of the newest duty hour restrictions, further limiting the working hours of first year residents and necessitating a variety of adaptations on the part of residency programs. The present study sought to characterize the perceived impact of these restrictions on residency program personnel using a multi-specialty and multi-site approach. METHODS: We developed and administered a survey to internal medicine and general surgery residency programs at three academic medical centers within an urban region. The survey combined quantitative and qualitative components to gain a broader understanding of the impact of the newest regulations. Quantitative responses were compared between Internal Medicine and General Surgery programs with Student t-tests. Other comparisons were performed using ANOVA or Kruskal-Wallis testing as appropriate. For all comparisons, the threshold for significance was set at 0.01. Two independent reviewers coded all qualitative data and assigned one or more themes based on content. Descriptive statistics were calculated and the diversity of themes identified. No between-group comparisons were conducted with the qualitative data. RESULTS: We found significant differences in the overall perceptions of duty hour restrictions across specialty (internal medicine more positive than general surgery) and across position (first year residents more positive than senior residents and faculty). Notably, individuals who trained at osteopathic medical schools reported significantly more negative views of the duty hour restrictions than those who had trained at allopathic or international medical schools, suggesting an influence of undergraduate medical training. The complementary qualitative data offered insights into the perceived strengths and weaknesses of the duty hour restrictions, as well as actionable suggestions that could help to improve residency program function. CONCLUSION: This study characterizes responses to the new duty hour restrictions from a variety of perspectives. Our findings show that individual (type of undergraduate medical education, role in graduate medical education) and program-wide (e.g., specialty) factors contribute to participant satisfaction with DHR. This research highlights the value of a mixed methods approach in the study of duty hour restrictions, with our qualitative arm yielding rich data that complemented and expanded upon the insights derived from the quantitative data.

Understanding the Effects of Health Care Distance Simulation: A Systematic Review.

ABSTRACT: The use of distance simulation has rapidly expanded in recent years with the physical distance requirements of the COVID-19 pandemic. With this development, there has been a concurrent increase in research activities and publications on distance simulation. The authors conducted a systematic review of the peer-reviewed distance health care simulation literature. Data extraction and a risk-of-bias assessment were performed on selected articles. Review of the databases and gray literature reference lists identified 10,588 titles for review. Of those, 570 full-text articles were assessed, with 54 articles included in the final analysis. Most of these were published during the COVID-19 pandemic (2020-2022). None of the included studies examined an outcome higher than a Kirkpatrick level of 2. Most studies only examined low-level outcomes such as satisfaction with the simulation session. There was, however, a distinction in studies that were conducted in a learning environment where all participants were in different locations ("distance only") as compared with where some of the participants shared the same location ("mixed distance"). This review exclusively considered studies that focused solely on distance. More comparative studies exploring higher level outcomes are required to move the field forward.

Distance simulation in the health professions: a scoping review.

BACKGROUND: Distance simulation is defined as simulation experiences in which participants and/or facilitators are separated from each other by geographic distance and/or time. The use of distance simulation as an education technique expanded rapidly with the recent COVID-19 pandemic, with a concomitant increase in scholarly work. METHODS: A scoping review was performed to review and characterize the distance simulation literature. With the assistance of an informationist, the literature was systematically searched. Each abstract was reviewed by two researchers and disagreements were addressed by consensus. Risk of bias of the included studies was evaluated using the Risk of Bias 2 (RoB 2) and Risk of Bias in Non-randomized Studies of Interventions (ROBINS-I) tools. RESULTS: Six thousand nine hundred sixty-nine abstracts were screened, ultimately leading to 124 papers in the final dataset for extraction. A variety of simulation modalities, contexts, and distance simulation technologies were identified, with activities covering a range of content areas. Only 72 papers presented outcomes and sufficient detail to be analyzed for risk of bias. Most studies had moderate to high risk of bias, most commonly related to confounding factors, intervention classification, or measurement of outcomes. CONCLUSIONS: Most of the papers reviewed during the more than 20-year time period captured in this study presented early work or low-level outcomes. More standardization around reporting is needed to facilitate a clear and shared understanding of future distance simulation research. As the broader simulation community gains more experience with distance simulation, more studies are needed to inform when and how it should be used.

Setting an Agenda: Results of a Consensus Process on Research Directions in Distance Simulation.

BACKGROUND: The COVID-19 pandemic forced rapid implementation and refinement of distance simulation methodologies in which participants and/or facilitators are not physically colocated. A review of the distance simulation literature showed that heterogeneity in many areas (including nomenclature, methodology, and outcomes) limited the ability to identify best practice. In April 2020, the Healthcare Distance Simulation Collaboration was formed with the goal of addressing these issues. The aim of this study was to identify future research priorities in the field of distance simulation using data derived from this summit. METHODS: This study analyzed textual data gathered during the consensus process conducted at the inaugural Healthcare Distance Simulation Summit to explore participant perceptions of the most pressing research questions regarding distance simulation. Participants discussed education and patient safety standards, simulation facilitators and barriers, and research priorities. Data were qualitatively analyzed using an explicitly constructivist thematic analysis approach, resulting in the creation of a theoretical framework. RESULTS: Our sample included 302 participants who represented 29 countries. We identified 42 codes clustered within 4 themes concerning key areas in which further research into distance simulation is needed: (1) safety and acceptability, (2) educational/foundational considerations, (3) impact, and (4) areas of ongoing exploration. Within each theme, pertinent research questions were identified and categorized. CONCLUSIONS: Distance simulation presents several challenges and opportunities. Research around best practices, including educational foundation and psychological safety, are especially important as is the need to determine outcomes and long-term effects of this emerging field.

Characterizing preferred terms for geographically distant simulations: distance, remote and telesimulation.

Background: Simulationists lack standard terms to describe new practices accommodating pandemic restrictions. A standard language around these new simulation practices allows ease of communication among simulationists in various settings. Methods: We explored consensus terminology for simulation accommodating geographic separation of participants, facilitators or equipment. We used an iterative process with participants of two simulation conferences, with small groups and survey ranking. Results: Small groups (n = 121) and survey ranking (n = 54) were used with distance, remote, and telesimulation as leading terms. Each was favored by a third of the participants without consensus. Conclusion: This research has deepened our understanding of how simulationists interpret this terminology, including the derived themes: (1) physical distance/separation, (2) overarching nature of the term and (3) implications from existing terms. We further deepen the conceptual discussion on healthcare simulation aligned with the search of the terminologies. We propose there are nuances that prevent an early consensus recommendation. A taxonomy of descriptors specifying the conduct of distance, remote and telesimulation is preferred.

Closing the gap: a call for a common blueprint for remote distance telesimulation.

The physical requirements mandated by the COVID-19 pandemic have presented a challenge and an opportunity for simulation educators. Although there were already examples of simulation being delivered at a distance, the pandemic forced this technique into the mainstream. With any new discipline, it is important for the community to agree on vocabulary, methods and reporting guidelines. This editorial is a call to action for the simulation community to start this process so that we can best describe and use this technique.

Mapping and morphometric analysis of synapses and spines on fusiform cells in the dorsal cochlear nucleus.

Fusiform cells are the main integrative units of the mammalian dorsal cochlear nucleus (DCN), collecting and processing inputs from auditory and other sources before transmitting information to higher levels of the auditory system. Despite much previous work describing these cells and the sources and pharmacological identity of their synaptic inputs, information on the three-dimensional organization and utltrastructure of synapses on these cells is currently very limited. This information is essential since an understanding of synaptic plasticity and remodeling and pathologies underlying disease states and hearing disorders must begin with knowledge of the normal characteristics of synapses on these cells, particularly those features that determine the strength of their influence on the various compartments of the cell. Here, we employed serial block face scanning electron microscopy (SBFSEM) followed by 3D reconstructions to map and quantitatively characterize synaptic features on DCN fusiform cells. Our results reveal a relative sparseness of synapses on the somata of fusiform cells but a dense distribution of synapses on apical and basal dendrites. Synapses on apical dendrites were smaller and more numerous than on basal dendrites. The vast majority of axosomatic terminals were found to be linked to other terminals connected by the same axon or different branches of the same axon, suggesting a high degree of divergent input to fusiform cells. The size of terminals was correlated with the number of mitochondria and with the number of active zones, which was highly correlated with the number of postsynaptic densities, suggesting that larger terminals exert more powerful influence on the cell than smaller terminals. These size differences suggest that the input to basal dendrites, most likely those from the auditory nerve, provide the most powerful sources of input to fusiform cells, while those to apical dendrites (e.g., parallel fiber) are weaker but more numerous.